Hillary Clinton will undoubtedly lose the South Carolina primary as African-Americans line up to vote for Barack Obama. And that defeat will power her drive to the nomination.

The Clintons are encouraging the national media to disregard the whites who vote in South Carolina’s Democratic primary and focus on the black turnout, which is expected to be quite large. They have transformed South Carolina into Washington, D.C. — an all-black primary that tells us how the African-American vote is going to go.

By saying he will go door to door in black neighborhoods in South Carolina matching his civil rights record against Obama’s, Bill Clinton emphasizes the pivotal role the black vote will play in the contest. And by openly matching his record on race with that of the black candidate, he invites more and more scrutiny focused on the race issue.

Of course, Clinton is going to lose that battle. Blacks in Nevada overwhelmingly backed Obama and will obviously do so again in South Carolina, no matter how loudly former President Clinton protests. So why is he making such a fuss over a contest he knows he’s going to lose?

If Hillary loses South Carolina and the defeat serves to demonstrate Obama’s ability to attract a bloc vote among black Democrats, the message will go out loud and clear to white voters that this is a racial fight.

It’s one thing for polls to show, as they now do, that Obama beats Hillary among African-Americans by better than 4-to-1 and Hillary carries whites by almost 2-to-1. But most people don’t read the fine print on the polls. But if blacks deliver South Carolina to Obama, everybody will know that they are bloc-voting.